压电惯性驱动器理论分析与应用测试

为了探究压电驱动器的输出性能及提高压电驱动机构的性能,该文对“十”字型压电惯性驱动器进行了理论分析与应用测试。首先说明了驱动器结构组成与驱动机理;然后利用弹性力学理论对驱动器进行了理论分析,得出驱动器弹性振动位移表达式,给出了影响驱动器性能的影响因素;最后对驱动器进行实验应用测试,将其用于驱动盲文柔性点显装置。结果表明,该驱动器能较好地实现系统驱动,放大柔性薄膜凸点的位移输出,柔性薄膜触点凸出明显,性能良好。验证了用这种压电惯性驱动器实现系统驱动是可行且有效的。     

新式压电精密旋转驱动器

提出一种新型将压电叠堆驱动元件应用到精密旋转驱动器上的研究方案。在对驱动器工作原理和机械结构进行分析研究的基础上,建立了以压电叠堆为驱动元件的旋转驱动数学模型。采用有限元分析软件对机械结构进行了分析,得到了机械结构工作方向的静力学变形图和频率响应特性曲线;对低频状态驱动器的旋转分辨率进行了试验测试,并对样机的频响特性进行了试验测试,结果表明仿真分析结果基本反映了机械结构的谐振频率分布状况,对结构优化设计具有一定的意义,此外对影响测试结果精度的因素进行了分析。设计的结构具有低频工作稳定、分辨率高(0.136 6μrad)等优点。     

电液伺服阀新型驱动器设计

针对传统的电液伺服阀分辨率较低、工作频带较窄及易受电磁干扰的特点,研制了一种由压电伸缩陶瓷驱动的新型驱动器．并对驱动机构的输出位移进行了测试。测试结果表明：该驱动器具有较大输出位移及较高的位移分辨率．可提高伺服阀的相关性能。     

一种高效压电旋转驱动器的设计和研究

为解决压电双晶片旋转驱动器能量利用效率低,转动力学性能差等问题,设计了一种高效压电旋转驱动器。驱动器以压电双晶片组为原动件,通过双离合器机构耦合,将双晶片组正、反两个方向产生的扭转运动全部转化为连续旋转输出,提高了能量利用效率。通过双晶片组对称结构的设计和安装,改善了驱动器力学性能和刚度。通过有限元仿真分析和实际测试,驱动器转速与驱动信号的频率电压基本成线性关系,驱动器承载能力明显提升。驱动器结构紧凑,体积小,普通正弦信号即可驱动,不需要特殊驱动信号或专门时序控制电路,运行稳定可靠,控制简单高效,适用于微驱动领域。     

基于自适应逆控制的压电驱动电源

为了减少压电驱动器迟滞非线性,提高微系统的定位精度,该文设计了基于自适应逆控制的压电驱动电源。选用型号TMSF320F28335的数字信号处理(DSP)芯片,对信号调节器、前级DC-DC的Boost升压电路和后级DC-AC的单相全桥逆变电路进行设计分析。在CCS6.0软件开发环境下进行编程,实现了SPWM驱动信号的生成、对位移信号进行AD采样和Prandtl-Ishlinskii自适应逆模型的功能。为了验证所设计的压电驱动电源的自适应控制性能,采用压电陶瓷驱动器开展了基于自适应逆的驱动控制实验。结果表明,在不采用控制的条件下,1 Hz时压电陶瓷驱动器的输出位移均方根误差(RMSE)为3.239 5 μm,绝对值平均误差(MAE)为2.985 1 μm;随着频率的增加,20 Hz时RMSE、MAE的最大值分别为21.402 9 μm、19.306 2 μm。使用基于自适应逆控制的压电驱动电源,1 Hz时RMSE为0.324 9 μm,MAE为0.265 6 μm;20 Hz时压电陶瓷驱动器的输出位移RMSE为12.639 μm,MAE为11.956 1 μm。     

用于微振动主动控制大位移压电堆驱动器设计

首先对压电堆驱动器的静态驱动特性进行了系统的理论分析,为压电堆驱动器的结构设计奠定理论基础。在此基础上,对压电堆驱动器的动态驱动特性及其结构模态等的测试方法进行了研究,从而为压电堆驱动器有效的应用于各类微振动主动控制系统奠定基础。最后设计并制作了一台大位移压电堆驱动器,对其各项性能进行了理论计算和实验测试,结果达到了预期设计要求,并成功应用于某微振动主动控制系统中,取得了良好的主动振动控制效果。     

基于分时驱动方法压电堆响应速度的研究

为提高压电驱动器响应速度,提出了一种超快速分时驱动方法。它通过考虑压电堆内部应力波传播对响应速度的影响,对各压电层进行分时驱动以提高其整体响应速度。通过COMSOL Multiphysics有限元仿真软件对所提出的模型进行了仿真分析,并通过实验结果得到了验证。相比于传统的同时驱动,分时驱动下压电驱动器的整体响应速度提高为原来的1.92倍;另外,分时驱动可以实现对各压电层产生应力的线性叠加,在不改变驱动器响应速度的前提下获得更大的输出位移。     

介电型EAP驱动的转动关节研究

基于介电型电活性聚合物(EAP)的优点,设计、实现了该材料驱动的转动关节。根据介电型EAP的变形原理设计、制作了圆柱形驱动器,其输出最大位移约为11mm,伸长应变达到33.8%,并对输出力-位移特性进行测试。基于该型驱动器实现了转动关节,转角约为±13°,堵转力矩为19.6mN.m,将转动关节应用于爬行机器人,并对试验结果进行分析。     

双向压电驱动的二维快速伺服刀架

快速伺服刀架能够提供精确、快速的微纳米级运动。为了获得双向和二维运动,该文研制了一种双向压电驱动的二维快速伺服刀架。该刀架采用对称结构设计,结合柔顺放大机构和位移解耦机构,末端执行机构实现较大的输出位移,同时减小耦合位移。基于伪刚体模型,建立快速伺服刀架的静力学和动力学模型,得到机构的输出位移、输出耦合比、最大应力和固有频率。通过有限元仿真验证了模型的正确性。最后,采用电火花线切割加工快速伺服刀架原型样机,并搭建了实验测试系统。实验结果表明,快速伺服刀架在x、y方向的位移放大率分别为3.56和3.57;输出耦合误差分别为1.26%和1.00%,装配压电陶瓷驱动器后系统在x、y方向的一阶固有频率均是270 Hz,系统动态性能良好。     

智能结构微位移测试及数值分析

对在压电陶瓷驱动下复合材料悬臂梁的静态变形及控制进行了试验研究.首先测试了复合材料基体和压电陶瓷片的材料常数;然后通过实验求得上下表面对称粘贴有分布式压电驱动器的复合材料悬臂梁静态位移与驱动电压间的非线性关系,所得结果与开发的4节点有限元计算结果相吻合.结果表明,利用压电陶瓷驱动器可对结构的微位移进行驱动,从而实现结构的精确定位.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.